Multimedia Broadcast Multicast Services (MBMS) are known for hierarchical Radio Access Network (RAN) architectures. See, for example, the Technical Specifications (TSs) TS 25.331 v8.20 and TS 25.346 v8.1.0, as promulgated by the Third Generation Partnership Project (3GPP). For hierarchical RANs, the typical approach is to coordinate MBMS over multiple base stations—e.g., NodeBs—using a radio network controller or other higher entity within the RAN architecture. However, that type of centralized control is not available in flat RAN architectures.
Ongoing work, as embodied in the 3GGP RAN3 working group, provides further teachings related to improving MBMS selective and/or soft combining, and Single Frequency Network (SFN) operation, in flat network architectures. Particularly, one may refer to the 3GGP Technical Report identified as TR R3.022 v0.3.0 (2008-05). This ongoing work focuses on user plane synchronization in flat RANs, but does not address practical solutions for MBMS control plane coordination and synchronization.